1. Continued studies of mutant mouse which stores cystine in lysosomes as do cystinotic patients; anamolies in cholesterol metabolism uncovered similar to: a) Niemann-Pick C cells which show lysosomal storage of cholesterol and lack of intracellular cholesterol esterification. b) Niemann-Pick D cells which do not store cholesterol but do show a lack of cholesterol esterification. 2. Finalization of the study of the glutathione cycle during growth in cystinotic versus normal cells. 3. Characterization of cystinotic cell metallathionein present in a 2-fold excess in cystinotic versus normal fibroblasts. 4. Inhibition of phospholipase A2 by uteroglobin. 5. Development of a cystinotic cell selection system based on the excretion of cysteine-cysteamine mixed disulfide into medium after treatment with pantethine by cystinotic cells and not found in medium from pantethine treated normal cells.